Patients with the paraneoplastic neurologic syndromes develop immunity to neural antigens expressed in their tumors, leading to effective anti-tumor immunity and autoimmune neurologic disease. Typically patients die from severe neurologic degeneration, for which there is no available treatment. We believe that treatment aimed at suppressing cellular immunity may have been overlooked as a treatment option in the paraneoplastic neurologic disorders, and are studying the effects of such immune suppression, using cyclosporin and prednisone, on clinical outcome.